it's something to do with your system being stuck in 32 bit mode. the "missing" ram has the addressing saved for your video card. i figured this problem out like 5 years ago on ubuntu, but don't remember where the fix was.

I'm a bit behind make ing a new one. I've got everything ready to go I just like to take my time looking up each new addition before I build he kernel.
I've been a noob for a long time:)_________________Without diversity there can be no evolution:)

It seems the maximum it is possible to install on that MB is 2Gb on each slot. The manual doesn't mention any sizes of memory that it recommends over 512Mb per slot which leads me to believe that the amount you put in was not tested at that stage. There is also mention of lowering the voltages on the motherboard for stability below that which the BIOS automatically sets which may help.

Unless it's to prove that you can is there any point in having the full 4Gb? On a motherboard that basic it's not really going to matter a lot.

I doubt this is fixable on your mainboard. The problem is PCI is limited to 32 bits, in order to map PCI above that an IOMMU is needed. You chipset probably does NOT have a IOMMU, thus it needs a memory "hole" between 3G-ish (often 3.5G or 3.75G) and 4G for the PCI DMA (similar reasoning applied to the ISA memory "hole" between 15M-16M for ISA DMA), as ISA DMA is limited to 24 bits)

Upgrayedd_________________I, for one, am glad to be living on a planet with 776x the mass of the super-massive black hole at the center of the milky way just to keep Neptune in its daily orbit around the Earth.
auf alten Schiffen lernt man Segeln.

I am guessing 768 is used for your on-board. Would leave you about 3.25 Gigs of ram Minus Various low level memory giving you 3.16. You can also run a "cat /proc/meminfo" to find out what your Motherboard truly says.

Even less effort required to be a help-desk vampire. I concur fully with BK now, except I think damaging a good hammer's peen smashing the motherboard would be unfortunate. Better to leave it under a neighbours front wheel, surreptitiously.

I am guessing 768 is used for your on-board. Would leave you about 3.25 Gigs of ram Minus Various low level memory giving you 3.16. You can also run a "cat /proc/meminfo" to find out what your Motherboard truly says.

Thanks for the line!
Here is my cat /proc/meminfo What does my board use?